Related Experiment Video

Updated: Jul 24, 2026

Use of Ultra-high Field MRI in Small Rodent Models of Polycystic Kidney Disease for In Vivo Phenotyping and Drug Monitoring
07:35

Use of Ultra-high Field MRI in Small Rodent Models of Polycystic Kidney Disease for In Vivo Phenotyping and Drug Monitoring

Published on: June 23, 2015

Birth weight and pathogenesis in phenylketonuria

D J Crockett1, L I Woolf, M S McBean

  • 1Department of Psychiatry, University of British Columbia, Vancouver, Canada.

The International Journal of Neuroscience
|October 1, 1990
PubMed

Insights

Infants with phenylketonuria (PKU) and their siblings have similar birthweights. Control infants were heavier, suggesting the PKU gene may influence birthweight, but not supporting the tyrosine deprivation hypothesis.

Area of Science:

  • Genetics
  • Pediatrics
  • Metabolic Disorders

Background:

  • Phenylketonuria (PKU) is an inherited metabolic disorder.
  • The "justification" hypothesis suggests PKU's neurological defects stem from prenatal tyrosine deprivation.
  • This hypothesis predicts lower birthweights in infants with PKU.

Purpose of the Study:

  • To compare birthweights of infants with PKU, their unaffected siblings, and control infants.
  • To investigate potential effects of the PKU gene on birthweight.
  • To evaluate the "justification" hypothesis regarding PKU pathogenesis.

Main Methods:

  • Birthweights were compared across three groups: infants with PKU, unaffected siblings, and controls.
  • Statistical adjustments were made for maternal age, obstetric history, gestation length, infant sex, and birth details.
  • An ethnically homogeneous sample was used to minimize confounding factors.

Main Results:

  • No significant birthweight differences were found between infants with PKU and their unaffected siblings.
  • Control infants exhibited statistically significant higher birthweights compared to the combined PKU and sibling groups.
  • This study reports a novel finding of the PKU gene's potential effect on birthweight.

Conclusions:

  • The PKU gene may have a subtle effect on birthweight, independent of PKU's pathogenesis.
  • Results do not support the "justification" hypothesis linking PKU's neurological deficits to prenatal tyrosine deprivation and lower birthweights.
  • Further research is needed to elucidate the mechanisms behind the observed birthweight differences.

More Related Videos

A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis06:19

A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis

Published on: January 7, 2018

Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 105:44

Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 1

Published on: May 17, 2024

Related Concept Videos

Overview of Protein Metabolism01:21

Overview of Protein Metabolism

Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Inborn Errors of Metabolism01:20

Inborn Errors of Metabolism

Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption01:23

Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption

Understanding the physiological differences in the pediatric population is crucial for effective pharmacotherapy. Neonates, infants, and children exhibit significant variations in gastric pH, gastric emptying time, intestinal transit time, and biliary function. These variations profoundly affect oral drug absorption, necessitating a nuanced approach to pediatric dosing.Neonates present with a unique physiological profile, having a gastric pH greater than 4 and faster and more irregular gastric...
Pharmacokinetics in Pediatric Patients: Drug Distribution01:17

Pharmacokinetics in Pediatric Patients: Drug Distribution

Drug distribution in the pediatric population exhibits unique challenges and considerations due to the physiological differences between children, particularly neonates and infants, and adults. A crucial aspect of pediatric pharmacology is understanding how these differences impact the pharmacokinetics of various drugs, necessitating age-specific dosing strategies to ensure efficacy and safety.Neonates and infants have a higher total body water content, ~75%–90% of their body weight, compared...
Pharmacokinetics in Pediatric Patients: Drug Metabolism01:24

Pharmacokinetics in Pediatric Patients: Drug Metabolism

In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
Pathophysiology of Diabetes01:20

Pathophysiology of Diabetes

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia. The four categories of diabetes are type 1 diabetes, type 2 diabetes, other specific types of diabetes, and gestational diabetes.
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...